Transport in animals Flashcards
circulatory system
system of blood vessels with a pump and valves to ensure one-way flow of blood.
In single circulation of fish
The blood passes through the heart once for one
complete circuit. It moves from the heart to the gills and then to the rest of the body.
Mammals have double circulatory system
One pulmonary loop and one systematic
loop happens in mammals. Blood passes through the heart twice for one complete
circuit.
Advantage of double circulation
high(er), blood pressure / flow rate (than single circulation) ;
allows different blood pressure in each loop ;
prevent mixing of oxygenated and deoxygenated blood ;
allows animals to have high metabolic rates ;
allows animals to be, large / tall ;
Blood is pumped away from the heart in
arteries and returns to the heart in veins.
The activity of the heart may be monitored by
ECG, pulse rate and listening to
sounds of valves closing.
Coronary heart disease is the blockage of
coronary arteries
CHD causes
diet, lack of exercise, stress, smoking, genetic predisposition, age and sex.
helps to reduce the risk of coronary heart disease
Balanced diet and exercise,They
reduce stress, lower blood pressure, make heart muscles stronger.
Atria
receives blood from either the lungs or the body and supply it to the ventricles. The ventricles pump blood out of the heart and all around the body. So pressure applied by the ventricles must be high. To help them do this, the ventricles have much thicker, more muscular walls than the atria.
The right ventricle
pumps blood to the lungs, which are very close to the heart
The left ventricle,
however, pumps blood to the rest of the body. The left ventricle has an
especially thick wall of muscle to enable it to do this.
Septum
separates oxygenated and deoxygenated blood in the heart.
As physical activity increases heart rate increase because
muscles contract more.
Muscles require more energy. More aerobic respiration takes place. More oxygen is
required. More blood is required to be transported to muscles for more oxygen.
Heart beats faster to supply more oxygen to the muscles.
Arteries:
Have thick walls
The diameter of lumen is small
No valves are present
Veins
Have relative thin walls
Diameter of lumen is large
Valves are present to prevent back flow of blood.
Blood pressure in arteries is
high because it has just been forced out of the heart by
the contraction of muscles of the ventricles. Arteries need very strong walls to
withstand this high pressure.
Blood in arteries doesn’t flow smoothly, it
pulses through. When ventricles contract
pressure in arteries is high and when ventricles relax pressure in arteries is reduced.
Arteries have elastic tissues in their walls which can stretch and recoil with the force
of the blood making the blood flow smoother.
Capillaries
very small and penetrate to every part of the body so that they can reach every cell.
The function of the capillaries is to
take nutrients, oxygen and other materials to all the
cells in the body, and to take away their waste materials. To do this, their walls must
be very thin so that substances can get in and out of the capillaries easily.
Veins function
return blood to the heart.
veins adaptation
Walls of veins (muscle and elastic tissue) are thin because there is no need for
strong walls as most of the blood pressure has been lost.
They have a wide lumen because it offers less resistance to blood flow.
Contain valves, that prevent backflow of blood.
Components of blood are
red blood cells, white blood cells, platelets and plasma
Red blood cells function
transporting oxygen. Haemoglobin is present in RBC and it combines with oxygen transports it.
White blood cells function
phagocytosis and antibody production
Platelets function
clotting
Plasma function
transport of blood cells, ions, nutrients, urea, hormones and
carbon dioxide
The roles of blood clotting are
preventing blood loss and prevent entry of pathogens.
Lymphocytes have
one big nucleus which covers almost the entire cell. Phagocytes
have a nucleus that divides into small connected balls.
Function of lymphocytes
is antibody production
